This project seeks a basis for more effective treatment of patients with malignant intracranial neoplasms through systemic examination of their experimental biology. The behavior of these neoplasms is being further defined by cellular and subcellular studies in cell cultures. Colony assay techniques have been developed to determine the effects of chemotherapeutic agents, steroids and ionizing radiation on cell viability. Analysis of drug effect has included studies on cell kinetics, biochemical mechanisms and enzymatic properties. An animal brain tumor model has been developed and is being assessed. The clinical efficacy of various oncolytic drugs, particularly those in the nitrosourea group, is being evaluated retrospectively. The prognosis and value of chemotherapy in medulloblastomas of childhood is under final review. BIBLIOGRAPHIC REFERENCES: Chen, T. T., and Mealey, J. Jr. Effect of nitrosoureas on human glioma cells. Proc. Amer. Assoc. Cancer Res., 16:165, 1975. Chen, T.T., Mora, E.C., and Mealey, J. Jr. Cultivation of medulloblastoma cells derived from Simian adenovirus SA7-induced hamster brain tumor. Can. Res., 35:3566-3570, 1975.